master branch: commit r16-7362 failed to bootstrap on Linux/x86_64 (commit r16-7357 builds)!

fi
make[2]: Entering directory '/export/home/haochenj/src/gcc-regression'
rm -rf bld
mkdir -p bld
cd bld; \
RUNTESTFLAGS="--target_board='unix{-m32,}'" ../src-master/configure \
	--with-arch=corei7 --with-cpu=corei7 --enable-clocale=gnu --with-system-zlib --enable-shared --enable-cet --with-demangler-in-ld --enable-libmpx --prefix=/usr/gcc-16.0.1 --with-fpmath=sse 
    grep -E "(error:|Error)" makelog.r16-7362.x86_64.corei7 >> makelog.r16-7362.x86_64.corei7.mail; \
    tail -n +20 makelog.r16-7362.x86_64.corei7 | grep -C 10 -E "error:|Error:" >> makelog.r16-7362.x86_64.corei7.mail; \
make[6]: [Makefile:1858: x86_64-pc-linux-gnu/bits/largefile-config.h] Error 1 (ignored)
make[6]: [Makefile:1857: x86_64-pc-linux-gnu/bits/largefile-config.h] Error 1 (ignored)
make[6]: [Makefile:1858: x86_64-pc-linux-gnu/bits/largefile-config.h] Error 1 (ignored)
/export/home/haochenj/src/gcc-regression/bld/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bits/hashtable.h:3020:5: error: ‘__heterogeneous_key’ was not declared in this scope
/export/home/haochenj/src/gcc-regression/bld/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bits/hashtable.h:3020:28: error: expected primary-expression before ‘,’ token
make[8]: *** [Makefile:1890: isl_test_cpp-isl_test_cpp.o] Error 1
make[7]: *** [Makefile:1997: all-recursive] Error 1
make[6]: *** [Makefile:1506: all] Error 2
make[5]: *** [Makefile:9446: all-stage2-isl] Error 2
make[4]: *** [Makefile:30949: stage2-bubble] Error 2
make[3]: *** [Makefile:31193: bootstrap] Error 2
make[2]: *** [Makefile:313: bootstrap] Error 2
==================== Detailed Info around error (+- 10 Lines) ====================
checking that generated files are newer than configure... done
configure: creating ./config.status
checking for sys/stat.h... yes
checking for stdlib.h... yes
checking for string.h... In file included from /export/home/haochenj/src/gcc-regression/bld/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bits/unordered_map.h:33,
                 from /export/home/haochenj/src/gcc-regression/bld/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/unordered_map:43,
                 from /export/home/haochenj/src/gcc-regression/bld/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/functional:80,
                 from ../../src-master/isl/include/isl/cpp.h:14,
                 from ../../src-master/isl/include/isl/typed_cpp.h:13,
                 from ../../src-master/isl/isl_test_cpp.cc:16:
/export/home/haochenj/src/gcc-regression/bld/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bits/hashtable.h:3020:5: error: ‘__heterogeneous_key’ was not declared in this scope
 3020 |     __heterogeneous_key<_Kt, _Container>;
      |     ^~~~~~~~~~~~~~~~~~~
/export/home/haochenj/src/gcc-regression/bld/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/bits/hashtable.h:3020:28: error: expected primary-expression before ‘,’ token
 3020 |     __heterogeneous_key<_Kt, _Container>;
      |                            ^
yes
checking for memory.h... yes
checking for strings.h... yes
checking for inttypes.h... yes
checking for stdint.h... yes
checking for unistd.h... yes
checking minix/config.h usability... no
checking minix/config.h presence... no